How to find out if you have 64bit or 32bit cpu / os (Linux)

1.Find out if your Linux OS (kernel) is 32 or 64 bit, type in terminal

uname -a

Output Example

2.6.31-16-generic #52-Ubuntu SMP Thu Dec 3 22:00:22 UTC 2009 i686 GNU/Linux

• If you see i386/i486/i586/i686 GNU/Linux you have a 32 bit kernel running.
• If you see x86_64 GNU/Linux you have 64 bit kernel.

2.Find out if your system (CPU) is 32 or 64 bit capable, type in terminal

grep flags /proc/cpuinfo

• If you see lm (long mode) in output, you have a 64 bit system.
• if you see pm (protected mode ) in you have a 32 bit system.
• if you see rm (real mode) you have 16 bit system.

Output Example

flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm tpr_shadow vnmi flexpriority

flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm tpr_shadow vnmi flexpriority

flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm tpr_shadow vnmi flexpriority

flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm tpr_shadow vnmi flexpriority